The present technology relates to a signal processing apparatus, a signal processing method, and a program, and in particular, relates to a signal processing apparatus capable of appropriately improving sound quality of an audio signal produced by, for example, decimating a portion of frequency components, a signal processing method, and a program.
When an audio signal is transmitted or recorded in a recording medium, the audio signal is encoded to reduce the amount of data of the audio signal.
When an audio signal is encoded, the amount of data of the audio signal is reduced by deleting, for example, a portion of frequency components from among frequency components of high frequencies.
Thus, a signal obtained by decoding encoded data obtained by encoding an audio signal lacks frequency components of high frequencies of an original sound, which is an audio signal before encoding, and the ambience is damaged and a muffled sound is generated, leading to lower sound quality.
Thus, a method of reproducing a signal of high sound quality by extending the frequency band (generating frequency components of high frequencies) based on frequency components of low frequencies of a signal obtained by decoding encoded data is proposed (see, for example, Japanese Patent Application Laid-Open No. 2008-139844).